Electric Long Bike

Introduction: Electric Long Bike

I built this electric bike for commuting to work. I stretched the rear triangle section partly because I wanted the extra cargo room and partly because I just liked the look. :-)

Step 1: Cutting and Welding

I started with a few curbside-recycling bikes which I welded together to make a stretched frame. I used a simple jig (made from parts of an old exercise bike) to try to keep things mostly straight ;-)

Step 2: Testing the Hub Motor

This show the initial testing of the hub motor and controller. I'm using a 20Ah 48V LiFePO4 battery, which is not shown in this photo. The hub motor, controller and battery were all purchased on EBAY.

Step 3: Rolling Chassis

Note the 2 kickstands. I need both due to the stretched frame and the battery weight.

Step 4: Final Touches

I'm happy with the performance of the bike. I can sustain 25 MPH with moderate pedaling and I can easily commute the 15 miles (each way) to work and the battery still has reserve charge when I return home. I installed a DC-to-DC converter (from an RC Hobby supplier) to generate 6 Volts to run the headlight and tail-light so all the electrics on the bike run from the 48V battery.

The bike has a 20Ah 48V lithium battery (check EBay). It was expensive, but in my opinion worth it because lithium batteries are much lighter and they last longer than lead-acid batteries. I have never really tested the battery to its limits so I can't say its absolute range and much depends on riding style, terrain, etc.

The tail light comes on when you turn on the bike main power. The head light comes on when you turn on the headlight. The headlight has flashing and non-flashing modes. Both tail light and head light are powered from the main battery.

Great instructable, I'm very happy to see how many people are using motorized bicycles to supplement or replace their dependence on cars.I do think that dogbeardbirdbeer has a point, in spite of the gruffness of his comment. Due to the lengthening of the frame, the bicycle is structurally weaker than it was originally. Specifically, the area between the seat post and the rear tire. You might avoid future problems by adding a pair of additional braces. I'd say the most efficient placement would be to divide the rear parallelogram into two triangles. In a line similar to the top/front of the rear tire. Just a thought.

In "Florida", any motorized vehicle needs a license and a plate for a motorcycle. Since there is a second law that states it is illegal to drive any motorized capable vehicle on sidewalks. (Even if you do not use the motor, it is motorized.) Thus, you are left driving on the road, and driving a motorized vehicle on the road requires a license and a tag. The only license and tag allowed on a non-car, is a motorcycle license and motorcycle tag.

Thus, any motor is legal, as long as all other road-vehicle requirements are met. (Mirrors, signal lights, breaks with adequate stopping power for the drive-system, helmet, and break-lights.)

Most states have similar DOT laws. Few states allow motorized vehicles on sidewalks, and most demand similar requirements for motorized vehicles on the roads. Just because you can't find the laws, or because you haven't been caught yet, or they don't actively enforce them... does not mean they don't exist. Ask your insurance company. That is when laws get actively enforced 100%. On the road, it is a lotto gamble.

The most expensive component was the 20AH LiFePO4 battery at about $400. You can get cheaper batteries at lower AH ratings or lower voltages but the20AH gives good range and is a good fit for this bike.The rear-wheel/hub motor/controller was the next most expensive at about $200.

Nice finished product - I can see why it's used as the title thumbnail for 'Electric Bikes'.

However, as others have noted, this really needs more (and more detailed ) instructions and insights:

What was the design process? - Why did you decide on this design over (any) others? What mistakes did you make - and how did you correct them? Explain to the layman why you put that extra tube behind the seat, down to the bottom forks (strength and support, presumably, but what led to its placement, given its lack in the first picture?) You came close to the sort of thing I'm talking about when you mentioned the 2 kick-stands.

Knowing my way around a bike as I do, along with some basics of bracing and welding, I can follow your texts and pictures to create a copy, but others aren't able to do so...

And, besides, I don't want to make a copy - I want to be inspired to expand and adapt stuff to my own wants and needs, which is so much easier when someone can warn you of the pitfalls.

My minibike has an A shaped kickstand. I hate it. I have to lean the bike up on buildings and stuff since that kickstand is terrible. It's great on smooth, perfectly flat pavement, and that's it. Any dirt, any hint of a hill, and the bike goes down. I have a moped that's much taller than that minibike, and I have a side kickstand on it with almost no problems.

Something I've found on the electric long bikes I've built, position of the batteries make a world of difference on how the bike handles. If you have a minute check out my bike, I've found this layout to be very transparent to how the bike handles.http://www.evalbum.com/2052

It's a good writeup of the finished product - not a very exceptional 'ible on the grounds that a layman would have a very difficult time reproducing your project from what you've provided...but awesome build!
I've got a veritable PILE of lipo batteries from ebay, soldered in parallel strings of 3... I could make a 'dumb' pack but it would have no balancing...and aparently lithiums dont like that.

well, they're fine with being unbalanced, until one goes above ~4.5v or one goes under 3.2v... then they swell, the capacity plumets, and eventually catch on fire.
It's pretty spectacular to watch actually, but... not fun to have happen!
Just get a balancing charger, they're not too expensive. Although a cheap one would likely have a low output meaning long charging times.
Anyways, I too would like to see more build info!